CN104865224B - For point amplitude type measuring method of smog medium scatters characteristic Muller matrix pattern - Google Patents

Abstract

The present invention relates to be used for point amplitude type measuring method of smog medium scatters characteristic Muller matrix pattern, belong to polarisation transfer field of detecting.Including emission system, smoky environment analog systemss, beam splitting system, reception system, computer processing system, occur the unstable phenomenons such as sedimentation in testing for aerosol gases medium, laboratory operating procedures are reduced as far as possible, ensure four tunnel reception systems while receiving detection, the method of testing that 16 kinds of existing minimal action are combined, four operations are reduced to, quick, the accurate validation of 16 scattering patterns in the Muller matrix obtained to Monte Carlo simulation is realized.The present invention can be according to actual test needs, select the smog medium of the difference test condition such as corresponding smog particle diameter, humidity, temperature, concentration, and be accustomed to according to the calculating of operator, adjust the compound mode of linear polarizer and quarter-wave plate in emission system and reception system, it is easy to operate, be easily achieved.

Description

Sub-amplitude Measuring Method for Mueller Matrix Pattern of Scattering Properties of Smoky Medium

technical field

The invention relates to a sub-amplitude measurement method for the Muller matrix pattern of the scattering characteristic of smoke medium, and belongs to the field of polarization transmission detection.

Background technique

At present, the phenomenon of smog weather caused by urban pollution is becoming more and more serious, which causes some media in the environment to attenuate the absorption and scattering of light. In order to study the interaction process between photons and particles in the smog medium, a Monte Carlo computer is used for a large number of photons The simulation method obtains the simulation pattern of 16 elements in the Mueller matrix of the smoke environment. Compared with other methods, this simulation method has the advantages of small influence of conditional restrictions, simple operation, and small simulation error.

In order to verify the correctness of the simulation results, the actual experimental method is used to obtain the scattering pattern for comparison. Since the 16 scattering patterns in the Mueller matrix need to be verified sequentially, at least 16 combinations are needed in the experiment to fully express each element in the Mueller matrix. Hielscher and National University of Defense Technology used 49 and 36 combinations respectively to complete the backscatter pattern test for liquid reflection. Fujian Normal University adjusted the polarizer and analyzer to horizontal, vertical, +45° line deviation and right-handed respectively. The 16 combinations of circular deviation directions can obtain the Mueller matrix pattern of the liquid sample, which saves a lot of experimental process. However, in the experiment, due to the impact of each adjustment on the accuracy of the detection results and the asynchrony of the records, the measurement accuracy is reduced, and it is difficult to meet the high accuracy requirements of computer simulation results verification. Moreover, the existing test methods mostly measure the scattering characteristics of stable liquids, and the phenomenon of unstable test environment caused by the settlement of smoke particles in the smoke gas environment has not been considered.

It can be seen that the verification method of the existing medium scattering Mueller matrix pattern is complex in operation and low in accuracy. Dozens of cumbersome experimental procedures are not suitable for the unstable characteristics of the smog medium. Validation is still a work in progress.

Contents of the invention

In order to adapt to the characteristics of the smog medium and study the verification method of the scattering characteristic Mueller matrix with simpler operation and higher testing accuracy, the invention proposes a sub-amplitude measurement method for the smog medium scattering characteristic Mueller matrix pattern.

The sub-amplitude measurement method for the scattering characteristics of the smog medium Muller matrix pattern, including the emission system, the smog environment simulation system, the spectroscopic system, the receiving system and the computer processing system, the emission system, the smog environment simulation system, the spectroscopic system, the receiving system and the The computer processing system is sequentially arranged on the optical path of the beam transmission;

The emission system includes a laser, a collimating beam expander system, a filter, a linear polarizer I and a quarter wave plate I, and taking the horizontal direction as the reference axis, the linear polarizer I and the quarter wave plate I The angle adjustment range is 0°～360° or removed;

The light splitting system includes a non-polarizing beam-splitting prism I, a non-polarizing beam-splitting prism II and a non-polarizing beam-splitting prism III. 1:1;

The receiving system includes a receiving unit I, a receiving unit II, a receiving unit III and a receiving unit IV; the receiving unit I includes a quarter-wave plate II, a linear polarizer II and a detector I; the receiving unit II includes A quarter-wave plate III, a linear polarizer III and a detector II; the receiving unit III includes a quarter-wave plate IV, a linear polarizing plate IV and a detector III; the receiving unit IV includes a quarter Wave plate Ⅴ, linear polarizer Ⅴ and detector Ⅳ; taking the horizontal direction as the reference axis, quarter wave plate Ⅱ, linear polarizer Ⅱ, quarter wave plate Ⅲ, linear polarizer Ⅲ, quarter wave plate The angle adjustment ranges of wave plate IV, linear polarizer IV, quarter wave plate V and linear polarizer V are all 0°～360° or removed;

The computer processing system is respectively connected to detector I, detector II, detector III and detector IV through data lines, and the computer processing system is connected to the smog environment simulation system;

Its characteristics are:

Implementation steps:

Step 1. Turn on the laser, and the emitted beam passes through the collimated beam expander system and enters the filter for filtering. The obtained collimated beam expanded parallel light passes through the linear polarizer I and the quarter wave plate I in turn, and is removed by removing or Adjust the angle of the linear polarizer I and the quarter wave plate I to polarize, with the horizontal direction as the reference axis, the angle adjustment range of the linear polarizer I and the quarter wave plate I are both 0° to 360°;

Step 2. The outgoing beam obtained in step 1 is incident to the smog environment simulation system, and the beam is incident to the beam splitting system through the smoke environment simulation system. By adjusting the placement positions of the three non-polarizing beam splitters in the beam splitting system, the beam is divided into four road, and the light intensity of each beam is the same;

The four beams obtained in step 3 and step 2 are injected into the four receiving units at the same time; the incident beams pass through the quarter-wave plate and the linear polarizer in turn on the four optical paths and then exit, and the four detectors detect the four beams at the same time. The light intensity of the outgoing beam, and the detection information is sent to the computer processing system, and the computer processing system performs pattern processing to obtain the light intensity pattern;

Step 4. After completing the above steps, the operator controls the smog environment in the smog environment simulation system through the computer processing system, and the particle radius parameter, refractive index parameter, humidity parameter, and concentration parameter of the smog environment in the smog environment simulation system are monitored by the computer processing system , temperature parameters, the computer processing system receives four sets of light intensity patterns of the beam emitted by the transmitting system at this time, and records the smoke environment in the smoke environment simulation system;

Step 5. Adjust the position of the linear polarizer I and the quarter-wave plate I in the transmitting system. Taking the horizontal direction as the reference axis, the angle adjustment range of the linear polarizer I and the quarter-wave plate I are both 0° ~360°; repeat step 4, and keep the smoke environment parameters in the smoke simulation system the same as those recorded in step 4;

Step 6 and Step 5 are repeated twice, and a total of 16 groups of light intensity patterns are obtained above, and the scattering patterns of 16 elements in the Mueller matrix of the smog medium scattering characteristics are obtained through a computer processing system.

The four-way receiving unit in the step 3 is adjusted by the following two methods respectively:

1) The quarter-wave plate II and linear polarizer II in the receiving unit I are removed to detect unpolarized light; the quarter-wave plate III in the receiving unit II is removed, and the linear polarizer III Adjust to the horizontal or vertical direction to detect horizontally or vertically polarized light; the quarter-wave plate IV in the receiving unit III is removed, and the linear polarizing plate IV is adjusted to +45° or -45° to the horizontal direction Direction, detecting linearly polarized light in the direction of +45° or -45°; the quarter-wave plate V in the receiving unit IV is adjusted to the direction of +45° or -45° with the horizontal, and the linear polarizer V Adjust to the horizontal direction to detect right-handed or left-handed polarized light;

2) The polarization analysis states in the four receiving units are to detect horizontally polarized light, vertically polarized light, linearly polarized light in the +45° direction, linearly polarized light in the -45° direction, right-handed polarized light, and left-handed polarized light Any four of them, but make sure that the four-way receiving unit has the detection of horizontally or vertically polarized light, +45° or -45° linearly polarized light, and right-handed or left-handed polarized light.

1. The sub-amplitude measurement method for the Mueller matrix pattern of the smog medium scattering characteristics according to claim 1, characterized in that: the linear polarizer I and the quarter wave in the emission system in the step 1 Plate I is adjusted four times in total to generate four sets of different polarized light, and ensure that the polarization state of the four sets of polarized light is the same as that of the analyzer in the four-way receiving unit.

The detectors I, II, III and IV are all CCD cameras.

Through the above design scheme, the present invention can bring the following beneficial effects: the present invention aims at the unstable phenomenon of the smog gas medium in the test, reduces the experimental operation steps as far as possible, and adopts the verification method of the Muller matrix pattern of the scattering characteristics of the sub-amplitude type smog medium, Reduce the existing test method of sixteen combinations with the least operations to four operations to ensure that the four receiving systems receive detection at the same time, and once the receiving system is determined, there is no need to adjust again. At the transmitting system end, each time the transmitting beam is adjusted , to re-monitor each parameter in the smog medium to ensure that the experimental environment is the same, and realize the rapid and accurate verification of the sixteen scattering patterns in the Mueller matrix obtained by Monte Carlo simulation in the smog medium. The present invention can select smoke media with different test conditions such as corresponding smoke particle size, humidity, temperature, concentration, etc. according to actual test needs, and adjust the linear polarizing plate and quarter of the transmitting system and receiving system according to the calculation habits of the operator. The combination of one wave plate is easy to operate and easy to realize.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing description and specific embodiment:

Fig. 1 is a schematic structural diagram of the system used in the sub-amplitude measurement method for the Mueller matrix pattern of the scattering characteristics of the smog medium according to the present invention.

In the figure: 1-Emission system, 101-Laser, 102-Collimation beam expander system, 103-Filter, 104-Linear polarizer Ⅰ, 105-Quarter wave plate Ⅰ, 2-Smoke environment simulation system, 3-Spectroscopic system, 401-receiving unit Ⅰ, 4010-quarter wave plate Ⅱ, 4011-linear polarizing plate Ⅱ, 4012-detector Ⅰ, 402-receiving unit Ⅱ, 4020-quarter wave plate Ⅲ, 4021-linear polarizer III, 4022-detector II, 403-receiving unit III, 4030-quarter wave plate IV, 4031-linear polarizer IV, 4032-detector III; 404-receiving unit IV, 4040- Quarter-wave plate V, 4041-linear polarizer V, 4042-detector IV; 5-computer processing system.

detailed description

As shown in the figure, for the sub-amplitude measurement method of the Mueller matrix pattern of the scattering characteristics of the smog medium, the required conditions and implementation steps are as follows:

Required conditions:

Including emission system 1, smog environment simulation system 2, spectroscopic system 3, receiving system, computer processing system 5;

The emission system 1 is composed of a laser 101, a collimating beam expander system 102, an optical filter 103, a linear polarizer I 104 and a quarter wave plate I 105, and taking the horizontal direction as the reference axis, the linear polarizer I and the The angle adjustment range of the quarter-wave plate I is 0°～360° or removed, which is used to generate polarized light in different states;

The smog environment simulation system 2 can generate various smog media such as water mist, oil mist and combustion-type soot, and is connected with a computer processing system 5, which is used to control and monitor the smog environment;

The beam-splitting system 3 is composed of three non-polarizing beam-splitting prisms I 301, non-polarizing beam-splitting prisms II 302, and non-polarizing beam-splitting prisms III 303 with a transmission and reflection energy ratio of 1:1. The beam-splitting system 3 is used to split a beam of light into four The three non-polarizing beam splitters do not change the polarization state of the polarized light, and only divide one beam of light into two beams of transmission and reflection, and the intensity is halved;

The receiving system is divided into four circuits, including receiving unit I 401, receiving unit II 402, receiving unit III 403 and receiving unit IV 404, and the components are the same, including a quarter-wave plate, a linear polarizing plate and a detector, wherein The quarter-wave plate and linear polarizer can be adjusted or removed for analysis, and the detector is a CCD camera to detect the light intensity pattern generated by the four beams;

The computer processing system 5 is connected with the detectors in the four-way receiving system and the smoke environment simulation system 2 through data lines.

Preferred embodiment:

Step 1: Turn on the laser 101, the emitted beam passes through the collimated beam expander system 102 and enters the filter 103 for filtering, removes the polarizer 104 and the quarter-wave plate 105 to generate unpolarized light, and enters the smog environment simulation system 2. The beam enters the beam splitting system 3 through the smog environment simulation system, and the beam is divided into four paths by the beam splitting system 3, and the light intensity of each beam is the same;

Step 2. The light beam obtained in step 1 is incident to the receiving system; the number of the receiving system is the same as the number of divided beams, and the number of receiving systems is four, which are respectively receiving unit I401, receiving unit II402, receiving unit III403 and Receiving unit IV404, the receiving unit I401 includes a quarter wave plate II4010, a linear polarizing plate II4011 and a detector I4012; the receiving unit II402 includes a quarter wave plate III4020, a linear polarizing plate III4021 and a detector II4022; The receiving unit III 403 includes a quarter wave plate IV 4030, a linear polarizing plate IV 4031 and a detector III 4032; the receiving unit IV 404 includes a quarter wave plate V 4040, a linear polarizing plate V 4041 and a detector IV 4042; each incident beam After passing through the quarter-wave plate and the linear polarizing plate in turn, the detector detects the light intensity of the outgoing beam, and the detector transmits the detection information to the computer processing system 5, and the computer processing system 5 performs pattern processing to obtain a light intensity pattern;

Step 3. Remove the quarter-wave plate II 4010 and linear polarizer II 4011 in the receiving unit I 401 in step 2 to detect unpolarized light; remove the quarter-wave plate in the receiving unit II 402 in step 2 Remove III4020 and adjust the linear polarizer III4021 to the horizontal direction to detect horizontally polarized light; remove the quarter-wave plate IV4030 in the receiving unit III403 in step 2, and adjust the linear polarizer IV4031 to the horizontal direction In the direction of +45°, detect the linearly polarized light in the direction of +45°; adjust the quarter-wave plate V4040 in the receiving unit IV404 in step 2 to the direction of +45° with the horizontal, and the linear polarizer V4041 Adjust to the horizontal direction to detect right-handed polarized light;

Step 4: After the processing in Step 3, the operator controls the smog environment in the smog environment simulation system through the computer processing system 5, and monitors parameters such as particle radius, humidity, and concentration in the smog environment, and the computer processing system 5 receives the transmitter Four groups of light intensity patterns for non-polarized light, and record the parameters of the smoke particles in the smoke environment simulation system 2 at this time;

Step 5. Place the linear polarizer I 104 behind the optical filter 103 described in step 1, and adjust it to the horizontal direction to polarize horizontally polarized light; adjust the computer processing system 5 to maintain the parameters of the smog environment in the smog simulation system 2 The same as the parameters recorded in step 4, obtain four sets of light intensity patterns when the emitter is horizontally polarized light at this time;

Step 6. Adjust the linear polarizer I 104 described in step 1 to the direction of +45° to the horizontal, and polarize the linearly polarized light in the direction of +45°; adjust the computer processing system 5 to keep the smog environment in the smog simulation system 2 The parameters are the same as the parameters recorded in step 4, to obtain four sets of light intensity patterns when the transmitting end is +45° polarized light at this time;

Step 7. Keep the linear polarizer I104 in step 1 in the horizontal direction, and then place the quarter-wave plate I105 behind it. The quarter-wave plate I105 is adjusted to a +45° direction from the horizontal, and the polarization is right-handed. Polarized light, adjust the computer processing system 5, keep the parameters of the smoke environment in the smoke simulation system 2 the same as the parameters recorded in step 4, and obtain four groups of light intensity patterns when the transmitter is right-handed polarized light at this time;

Step 8: Sixteen groups of light intensity patterns obtained through steps 4 to 7, the 16 groups of light intensity patterns are respectively I ₀₀ to I ₃₃ , and the representation methods of I ₀₀ to I ₃₃ are shown in Table 1, and The formula (1) calculates the scattering pattern of sixteen elements in the Mueller matrix of the scattering characteristics of the smog medium in turn.

Table 1 Representation of I ₀₀ ~ I ₃₃

S' ₁₁ =I ₀₀ , S' ₁₂ =I ₁₀ -I ₀₀ , S' ₁₃ =I ₂₀ -I ₀₀ , S' ₁₄ =I ₃₀ -I ₀₀ ,

S' ₂₁ =I ₀₁ -I ₀₀ , S' ₂₂ =I ₁₁ -I ₀₁ -I ₁₀ +I ₀₀ , S' ₂₃ =I ₂₁ -I ₀₁ -I ₂₀ +I ₀₀ , S' ₂₄ =I ₃₁ -I ₀₁ -I ₃₀ +I ₀₀

S' ₃₁ =I ₀₂ -I ₀₀ , S' ₃₂ =I ₁₂ -I ₀₂ -I ₁₀ +I ₀₀ , S' ₃₃ =I ₂₂ -I ₀₂ -I ₂₀ +I ₀₀ , S' ₃₄ =I ₃₂ -I ₀₂ -I ₃₀ +I ₀₀

S' ₄₁ =I ₀₃ -I ₀₀ , S' ₄₂ =I ₁₃ -I ₀₃ -I ₁₀ +I ₀₀ , S' ₄₃ =I ₂₃ -I ₀₃ -I ₂₀ +I ₀₀ , S' ₄₄ =I ₃₃ -I ₀₃ -I ₃₀ +I ₀₀ (1)

The measurement of the Mueller matrix pattern of the scattering characteristics of the smog medium can be completed by using the above steps.

The above-mentioned embodiments are only illustrative methods and beneficial effects of the present invention, and are not intended to limit the present invention. Anyone familiar with this method can modify the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention should be as listed in the scope of the patent application.

Claims (4)

1. A sub-amplitude measurement method for the Mueller matrix pattern of the scattering characteristics of the smog medium, including a transmitting system (1), a smog environment simulation system (2), a spectroscopic system (3), a receiving system and a computer processing system (5), The transmitting system (1), the smog environment simulation system (2), the spectroscopic system (3), the receiving system and the computer processing system (5) are sequentially arranged on the optical path of the beam transmission; The emission system (1) includes a laser (101), a collimated beam expander system (102), an optical filter (103), a linear polarizer I (104) and a quarter wave plate I (105), and the The horizontal direction is the reference axis, and the angle adjustment ranges of linear polarizer I (104) and quarter wave plate I (105) are both 0° to 360° or removed; The beam splitting system (3) includes non-polarizing beam-splitting prism I (301), non-polarizing beam-splitting prism II (302) and non-polarizing beam-splitting prism III (303), and non-polarizing beam-splitting prism I (301), non-polarizing beam-splitting prism II (302) and the ratio of the transmitted energy to the reflected energy of the non-polarizing beam splitter III (303) are both 1:1; The receiving system includes receiving unit I (401), receiving unit II (402), receiving unit III (403) and receiving unit IV (404); the receiving unit I (401) includes a quarter-wave plate II ( 4010), linear polarizer II (4011) and detector I (4012); the receiving unit II (402) includes quarter-wave plate III (4020), linear polarizer III (4021) and detector II ( 4022); the receiving unit III (403) includes a quarter wave plate IV (4030), a linear polarizer IV (4031) and a detector III (4032); the receiving unit IV (404) includes a quarter One wave plate V (4040), linear polarizer V (4041) and detector IV (4042); taking the horizontal direction as the reference axis, quarter wave plate II (4010), linear polarizer II (4011), four Quarter-wave plate III (4020), linear polarizer III (4021), quarter-wave plate IV (4030), linear polarizer IV (4031), quarter-wave plate V (4040) and linear polarizer The angle adjustment range of sheet Ⅴ (4041) is 0°～360° or removed; The computer processing system (5) is respectively connected to detector I (4012), detector II (4022), detector III (4032) and detector IV (4042) through data lines, and the computer processing system (5) is connected to Smoke environment simulation system (2) connection; Its characteristics are: Implementation steps: Step 1: Turn on the laser (101), the emitted light beam passes through the collimated beam expander system (102) and enters the optical filter (103) for filtering, and the obtained collimated beam expanded parallel light passes through the linear polarizer I (104) and Quarter-wave plate I (105), polarized by removing or adjusting the angle of linear polarizer I (104) and quarter-wave plate I (105), with the horizontal direction as the reference axis, the linear polarizer The angle adjustment ranges of I (104) and quarter-wave plate I (105) are both 0° to 360°; Step 2. The outgoing light beam obtained in step 1 is incident to the smog environment simulation system (2), and the light beam is incident to the beam splitting system (3) through the smoke environment simulation system (2), and the three non-polarized beam splitters in the beam splitting system (3) The placement position of the prism, the light beam is divided into four paths by the beam splitting system (3), and the light intensity of each light beam is the same; The four beams obtained in step 3 and step 2 are injected into the four receiving units at the same time; the incident beams pass through the quarter-wave plate and the linear polarizer in turn on the four optical paths and then exit, and the four detectors detect the four beams at the same time. The light intensity of the outgoing light beam, and the detection information is sent to the computer processing system (5), and the computer processing system (5) performs pattern processing to obtain the light intensity pattern; Step 4. After completing the above steps, the operator controls the smog environment in the smog environment simulation system through the computer processing system (5), and the particle radius parameter, Refractive index parameters, humidity parameters, concentration parameters, and temperature parameters are received by the computer processing system (5) to receive four sets of light intensity patterns of the light beam emitted by the transmitting system at this time, and record the smoke environment in the smoke environment simulation system (2); Step 5. Adjust the placement position of the linear polarizer I (104) and the quarter wave plate I (105) in the transmitting system, with the horizontal direction as the reference axis, the linear polarizer I (104) and the quarter wave plate The angle adjustment range of Ⅰ (105) is 0° to 360°; repeat step 4, and keep the smoke environment parameters in the smoke simulation system (2) the same as the parameters recorded in step 4; Step 6 and Step 5 are repeated twice, and a total of 16 groups of light intensity patterns are obtained above, and the scattering patterns of 16 elements in the Mueller matrix of the smog medium scattering characteristics are obtained through the computer processing system (5). 2. the sub-amplitude type measurement method for the smog medium scattering characteristic Muller matrix pattern according to claim 1, is characterized in that: the four-way receiving unit in the described step 3 is adjusted by the following two methods respectively: 1) The quarter-wave plate II (4010) and linear polarizer II in the receiving unit I (401) are removed (4011) to detect unpolarized light; a quarter wave plate II (402) in the receiving unit II (402) A wave plate III (4020) is removed, and the linear polarizer III (4021) is adjusted to the horizontal or vertical direction to detect horizontally or vertically polarized light; the quarter wave plate IV in the receiving unit III (403) (4030) is removed, and the linear polarizer IV (4031) is adjusted to a direction of +45° or -45° with the horizontal direction to detect linearly polarized light in the direction of +45° or -45°; the receiving unit IV ( The quarter-wave plate V (4040) in 404) is adjusted to a +45° or -45° direction with the horizontal, and the linear polarizer V (4041) is adjusted to the horizontal direction to detect right-handed or left-handed polarized light; 2) The polarization analysis states in the four receiving units are to detect horizontally polarized light, vertically polarized light, linearly polarized light in the +45° direction, linearly polarized light in the -45° direction, right-handed polarized light, and left-handed polarized light Any four of them, but make sure that the four-way receiving unit has the detection of horizontally or vertically polarized light, +45° or -45° linearly polarized light, and right-handed or left-handed polarized light. 3. the sub-amplitude measurement method for the smog medium scattering characteristic Muller matrix pattern according to claim 1, characterized in that: the linear polarizer I (104) and the quadrant in the emission system in the step 1 One of the wave plates I (105) is adjusted four times in total to generate four sets of different polarized lights, and ensure that the polarization states of the four sets of polarized lights are the same as those of the analyzers in the four receiving units. 4. the sub-amplitude measurement method for the smog medium scattering characteristic Muller matrix pattern according to claim 1, characterized in that: said detector I (4012), detector II (4022), detector III ( 4032) and detector IV (4042) are CCD cameras.